Tissue engineering of small-and large-diameter blood vessels

Abstract

Today, atherosclerotic vascular diseases such as coronary and peripheral vascular disease are one of the leading causes of death in the western world (www.americanheart.org/presenter.jhtml?identifier=4440). The prevalence of arterial disease is increasing in the aging society (Baguneid et al. 1999) and is currently estimated up to 20% (AHA 2006). Many of the patients with atherosclerotic vascular diseases suffer from angina or myocardial infarction or critical limb ischemia. If left untreated, the patient's quality of life will be restricted due to the symptoms of the advanced state of the disease and major amputation might be required. Advanced treatment and therapies such as endovascular or minimally invasive procedures and surgical reconstruction significantly increase the quality of life (www.vascularweb.org/-CONTRIBUTION- PAGES/Patient-Information/NorthPoint/Endovascular-Stent-Graft.html). For lower limb artery bypass the autologous saphenous vein represents the accepted "gold standard" vascular graft (Taylor et al. 1990), while the internal mammary artery is the preferred graft for coronary artery bypass (Cameron et al. 1996). A major drawback and cause of failure of venous grafts is occlusion (stenosis) that is a consequence of the systemic pressure-induced tissue degeneration. One-third of vein grafts are occluded within 10 years and half of those show marked atherosclerotic changes (Raja et al. 2004). Furthermore, 30% of patients undergoing lower limb bypass do not have suitable veins (Veith et al. 1979) and suitable arterial grafts for coronary bypass (Seifalian et al. 2002) because of pre-existing diseases or because they have already been used in previous treatments (Clayson et al. 1976, Darling and Linton 1972). This shortage restricts this therapeutic approach. Thus, an alternative vascular replacement material with native analogous characteristics is highly needed, especially in the light of the increasing multi-morbidity of aging patient population. Currently, most coronary artery bypass grafting operations are performed using combinations of internal mammary artery and saphenous vein. Beside a need for small diameter grafts such as for the coronary arteries or peripheral blood vessels, there is also a lack of appropriate materials for the replacement of large diameter vessels such as for a diseased aorta or for the repair of congenital cardiovascular malformations. In order to overcome these limitations, the search for alternative materials leading to biocompatible and anti-thrombogenic vascular substitutes has been undertaken by many research groups worldwide. Many types of vascular substitutes have been proposed. These include fresh or cryopreserved allografts, decellularized tissues, and artificial synthetic grafts. © Springer Science+Business Media, LLC 2009.